Illegal Pesticide Residue Problem in the East China Sea - June 1999

Illegal Pesticide Residue Problem in the East China Sea - June 1999

According to a survey conducted by the National Institute for Environmental Studies, the presence of organochlorine pesticides, specifically Hexachlorocyclohexane (HCH), which are banned substances, was confirmed in the East China Sea. This substance was once widely used in China and Southeast Asia, but its use is now prohibited in many countries. However, the survey detected HCH at a concentration of 65 picograms per liter of seawater about 200 km west of Amami Oshima. Moreover, a more severe concentration was found in the central part of the East China Sea, reaching 458 picograms per liter, raising concerns about environmental impact.

The cause of this pesticide residue is believed to be the inflow from the Yangtze River. The Yangtze River is China's largest river, and its basin is an agricultural hub where HCH was extensively used in the past. As a result, pesticides from agricultural activities in the Yangtze River basin are thought to have flowed into the sea through the river, eventually reaching the East China Sea after passing through industrial cities such as Shanghai and Nanjing.

Furthermore, an interesting aspect of this issue is that China's agricultural enterprises and local governments have been slow to address the problem. Reports indicate that the contamination of agricultural water sources and its impact on fishery resources have worsened. Coastal areas such as Dalian and Qingdao have experienced marine pollution, affecting the safety of marine products.

What is unique about this problem is that HCH was not used illegally but rather that pollution caused by its past use has persisted over time. This kind of "residual pesticide" issue differs from other pesticide pollution cases in that the pesticides, used in large quantities in the past, remain in the environment for long periods, continuing to affect the marine ecosystem.

As a result, international cooperation is required among countries surrounding the East China Sea to manage pesticides and combat marine pollution. Countries such as Japan, China, and South Korea need to work together to address this issue.